Process for the manufacture of abrasive articles



Patented Jan. 30, 1940 UNITED STATES ,PROOESS FOR THE MANUFACTURE OF ABRASIVE narrows Ernst Elb'el and Fritz Seebach, Erkner, near Berlin, Germany, assignors, by mesne assignments, to Bohr-Manning Corporation, Troy, N. Y., a corporation of Massachusetts 7 No Drawing. Application December 24, 1931,se-

. rial No. 583,145. In Germany December 30,

11- Claims. v(o1. 51-280) Abrasive papers and the like are in general so prepared that on a base, for example, paper or linen, any type of adhesive is applied on which 7 the emery powder is sprinkled or pressed. The

5 adhesive to be used has to combine various characteristics. In the first place it should befiexible so that the abrasive paper conforms well to, the

object operated upon without detachment of the abrasive layer.

should be quite water-rmistant and s'houldnot soften, as this decreases the efliciency of the abrasive paper.

We have observed that abrasive papers thereby including cloth or other suitable fabric base,

ll of remarkable flexibility and resistance will be,

obtained if ih their manufacture hardenable resinous products which are used as adhesives obtained by digesting phenol-aldehyde resins and -iatty oils to a homogeneous condition. Hardenable condensation products, for example, resoles prepared from cresol and formaldehyde-in the presence 01 ammonia, can be heated with com pletely or partly oxidized air drying oils, preferably in the presence of a solvent or solvent mixture, dissolving both components, until the con-- densation products and the air drying oilsbegin to homogenize. According to another method hardenable phenol-aldehyde condensation products or resoles can be heated with tung oil in the 3 presence of liquids, as for example methyl-cyclohexanol or acetone which dissolve both materials and permit the combination of resoles with tung oil at a temperature below 150'. According to a third method novolaks can be dissolved infatty air drying oils by heating and converting them whilein solution into hardenable resins by the action of hardening agents. After the fusion has taken place in the presence of solvents, the solvents can be distilled off wholly or partly from 40 the product'obtained. Instead of the resoles one can also use their derivatives, for example acetylderivatives of the resoles. Before, during or after the preparation of the composite products of hardenable resins and fatty oils, other resins, for 46 example natural or synthetic resins can be added to them. The composite products embodying hardenable resins in rescle condition can be used as such; one may also proceed by heating the composite products for example to the B condi- 50 tion or a less polymerized condition, and using them in this pre-hardened condition in the manner'described hereafter. Y

As an illustration a resinous product as described above for example one dissolved in wood alcohol or in spirit benzol, is applied to a base In the next place the adhesive ticizers.

'material and the abrasive is then sprinkled on it. v

A continuous paper sheet so treated can be dried in an oven, for example at approximately C.

, One may even operate by running the base material over a metal plate. heated from below f or 8 interiorly by means of a gas flame; care is to be taken that the paper runs in close contact to the heated plate as for example by means of a wooden roller; The higher the temperature of the heated plate, the more rapidly can the abrasive paper be 10 run as a continuous sheet over the heating device. The resinous binder can be sprayed on the base not only as a solution but" also as an emulsion. One can also spray theabrasive powder on the base togetherwith the dissolved resin, or one can 1 mix the abrasivewith the dissolved resin before spraying. Finally the process can also be carried out by sprinkling not only the powdered abrasive on the base, but also the pulverized resinous binder, either successively or simultaneously after mixing them in the usual manner. Instead of emery one can, of course, also use other suitable abrasives, and one can use the binders as specified in mixture with other wellknown binders. Organic or inorganic dyes, plasor fireprooflng materials may also be added to the mixture of resinous binders and abrasives.

We claim:

1. Process of preparing an abrasive article a which comprises applyingto a flexible base abrasive grains and a binder including a heat-hardening composition of a phenol-aldehyde resin brought into homogeneous solution with a drying oil, and heating to cause setting of the binder to u a solid fllm' characterized by adherence, flexfigity, water resistance and freedom from soften- 2. Process of preparingan abrasive article which comprises applying to a flexible base abrasive grains and a binder including a heathardening composition of a phenol-aldehyde resin brought into homogeneous solution with a drying oil in the presence of a common solvent, removing the solvent, and heating to cause setting of the binder to a solid film characterized by adherence, flexibility, water resistance and freedom from softening.

3. Process of preparing an abrasive article which comprises applying to a flexible base abrasive grains and a binder including a heat-hardening composition of a phenolealdehyde resin brought into homogeneous solution with an oxidized drying oil, and heating to cause setting of the binder into a solid film characterized by N adherence, flexibility, water resistance and freedom from softening. Y

4. Process of preparing 'an abrasive article which comprises applying to a flexible base abrasive grains and a binder of a fusible phenol- ;aldehyde resin brought into homogeneous solution with a drying oil and converted to a heathardening composition by means of a hardening agent, and heating to cause setting of the binder ibility, water resistance and freedom from soften-v 5. Abrasive article comprising a flexible base, abrasive grains and a binder for securing the grains to the base, said binder comprising a heathardened solid composition of a phenol-aldehyde resin brought into homogeneous solution with a drying oil and characterized by adherence, flexibility, water resistance and freedom from softengoin 7. Abrasive article comprising a flexible base,

abrasive grains and a binder for securing the grains to the base, said binder comprising a heathardened solid composition of a phenol-aldehyde resin brought into homogeneous solution with tung oil and characterized by adherence, flexito a solid film characterized by adherence, flexe "ing material, said binder comprising a polymerized complex of a phenol aldehyde reaction product in homogeneous solution with a drying oil.

9. An abrasive article of the nature of sandpaper comprising a composite sheet of flexible backing material, a layer of abrasive particles,

and a binder uniting said particles to the backing material, said binder comprising ,a polymerized and oxidized complex of a phenol aldehyde reaction productin homogeneous solution with a. drying oil.

10. A process for producing an article of the nature of sandpaper which comprises applying to a flexible backing material abrasive particles and a binding composition comprising a phenol aldehyde reaction product in homogeneous solution with a drying oil, and polymerizing the binding composition.

11. A process for producing an article of the nature of sandpaper which comprises applying to a flexible backing material abrasive particles and a binding composition comprising a phenol aldehyde reaction product in homogeneous solution with a drying oil, and polymerizing and oxidizing the binding composition.

' ERNST ELBEL.

FRITZ SEEBACH. 

